#include<iostream>
#include<string.h>
using namespace std;
int main()
{


	int flag=1;
	string x;
	cin>>x;
	int len=x.length();
	for(int i=0;i<len;++i)
	{
		if(x[i]!=x[len-1-i])
		{
			flag=0;
			break;
		}
	}
	if(flag) cout<<"yes"<<endl;
	else cout<<"no"<<endl;

}
